Centrifugal atomizer manufacturer: take you to understand the structure of centrifugal atomizer


The centrifugal atomizer equipment consists mainly of a spray chamber, a sprayer (including a spray plate) and a hot air plate. The diameter of the spray chamber is related to the slow speed of the centrifugal nozzle. The diameter of droplets is inversely proportional to the velocity. The range of droplets is proportional to the diameter of droplets. That is, when the speed is small, the range of droplets is larger, and the tower diameter varies with the range, so the smaller the nozzle speed, the larger the nozzle diameter. In the spray moment as the radius of the circle, 90%-95% of the droplets fall, that is, no longer have horizontal velocity, this distance is called the spray moment, as long as the diameter of the drying tower is greater than the spray moment, most droplets will not hit the wall, usually the spray chamber cross-sectional wind speed should be 0.1-0.4m / s.

  In the middle of the spray chamber, there are walkways and escalators for workers to clean the tower walls. After drying is complete, the room is ventilated and cooled, and personnel remove the centrifugal spray pans from the escalator for cleaning. In some plants, the entire electric sprayer is lifted by electric hoist to the top of the drying tower and then the spray pan is removed for sliding washing. The former is good because although ventilation and cooling are still performed after shutdown, the temperature in the tower is still high, especially in summer, and this prevents people from entering the tower. The spray chamber should be equipped with a tower door (manhole), light hole, observation hole, thermometer, mercury vacuum gauge, etc. The tower door should be installed on the side of the aisle so that it can be cleaned after the machine has stopped. The inner wall of the tower should be smooth. Try to avoid hanging powder. Use asbestos, wood chips or expanded perlite as insulation for the outer walls of the tower.

  There are flat plate, disc, bowl, multi-wing, lance, cone and cap types, but the latter three are currently used for enzyme production. The lance type consists of a set of nozzles (usually 6) extending to the outside of the centrifugal disc. Like a wing wheel, a negative pressure is created in the center. The sprayed material easily rolls up and sticks to the top wall. Conical and round cap shapes avoid this problem. The latter two forms have proven to be better in production practice, with the nozzle outlet of the round cap shape tilted downward at 45° to avoid spinning the sprayed material upward. The conical spray plate is a set of nozzles mounted on a centrifugal disc that avoids the creation of negative pressure in the center, which can cause the material to stick to the top wall. The material of the spray plates and nozzles is made of stainless steel. The machining accuracy of the shaft and centrifugal plate is required to be class II. A dynamic balance test is required during handling and installation. Otherwise, if the weight is not balanced, it will vibrate and the bearings will be easily damaged.

  Uneven distribution of hot air entering the tower is the main reason for local adhesion of the tower. Most of the hot air enters the tower through the wind from the hot air plate (i.e. internal air duct), except for a portion of the hot air that enters the tower through a fixed and evenly distributed square inlet on the outside of the tower. Directional adjustment plate. The downward tilt angle of the air direction adjustment plate can be adjusted and the direction of the hot air entering the tower can be the same or opposite to the direction of the material and liquid thrown by the jet plate. In order to equalize the velocity of the hot air entering the tower over the hot air plate, the hot air plate is usually in the shape of a worm shell and the hot air enters the hot air distribution plate at a high velocity of 6-10m / s. The hot air distribution plate should be installed together with the sprayer. The sample inlet and the spraying plate should be located as close as possible. The hot air distribution plate should distribute the hot air evenly into the spray chamber. Therefore equal velocity into the tower is required to avoid and minimize the formation of vortexes as much as possible. Otherwise material coking will easily occur. The outlet air velocity of the hot air distribution plate is typically 8-12 m / s. Due to the high speed rotation of the spraying plate, a negative pressure is created in the center, which causes the thrown material to curl up and stick to the sprayer, i.e., this is a dead spot where the hot air cannot be blown away. A small amount of hot air can be introduced around the sprayer during the design process to avoid this phenomenon.